Field of the Invention and Related Art Statement
The present invention relates to an ultrasonic probe, and more particularly to an improvement of the ultrasonic probe for use in ultrasonic endoscope, ultrasonic diagnosing apparatus and other ultrasonic apparatuses.
There has been described a known ultrasonic probe in Japanese Utility Model Application Laid-open Publication Kokai Sho 60-45007.
FIG. 1 shows the known ultrasonic probe disclosed in said Publication. The ultrasonic probe comprises an ultrasonic vibrator 105 which includes a stack of piezoelectric vibrating element 105a, backing member 105b applied on a back side of the vibrating element and an acoustic matching layer 105c. The ultrasonic vibrator 105 is secured to a lower casing 102 which is provided at a tip of an upper casing 101. One lead wire 106a connected to an electrode applied on one surface of the piezoelectric element 105 is extended within an opening 104 formed in the lower casing 102 and the other lead wire 106b connected to an electrode applied on the other surface of the piezoelectric element 105 is extended along an outer surface of the lower casing 102. These lead wires 106a and 106b are further extended within the lower casing 102. Within the opening 104 is filled with a damper 107. Further the lower casing 102 is covered with a cap-like casing 103.
In the known ultrasonic probe mentioned above, the ultrasonic vibrator 105 and damper 107 are provided within the lower casing 102 when the lower casing is formed by molding. Then the cap-like casing 103 is also formed integrally with the lower casing 103 by molding.
FIG. 2 shows another known ultrasonic probe in which an ultrasonic vibrator 201 having lead wires connected to the electrodes is fixed within a casing 203 together with a damper 202 when the casing 203 is formed by molding. After that a resilient member 204 made of urethane rubber is secured to the casing.
In the known ultrasonic probe described in the Japanese Utility Model Application Publication Kokai Sho 60-45007, it is necessary to connect the lead conductors 106a and 106b to the electrodes of the ultrasonic vibrator 105. This results in that when the ultrasonic vibrator 105 is placed in a mold for forming the lower casing 102, the lead conductors might be cut, so that yield is liable to be low. Further it is practically difficult to provide a reference member for positioning the ultrasonic vibrator 105 within the mold, and therefore the ultrasonic vibrator is liable to be tilted or shifted.
The known ultrasonic probe illustrated in FIG. 2 has the same drawbacks as those mentioned above.